LM3405XMKX/NOPB - 1A 1.6MHz Constant-Current Buck LED Driver | TI
Teilenummer: LM3405XMKX/NOPB ✓ Aktiv| Menge | Stückpreis | Gesamt |
|---|---|---|
| 1 | $1.62 | $1,62 |
| 10 | $1.45 | $14,50 |
| 100 | $1.18 | $118,00 |
| 500 | $0.98 | $490,00 |
| 1.000 | $0.84 | $840,00 |
LM3405XMKX/NOPB Übersicht
An LED driver is a semiconductor device that regulates current through one or more LEDs to ensure consistent luminance, color, and reliability. Constant-current buck (step-down) LED drivers are a sub-category of switching power converters that combine a power MOSFET, inductor current-sense amplifier, and feedback loop. They sit within the broader taxonomy of LED drivers > power management ICs > semiconductors. Their main role is to convert a higher DC bus voltage (e.g., 5V, 12V, or a Li-Ion cell) into a precisely regulated LED string current, eliminating the efficiency loss and thermal stress of a series resistor.
Key features include a 3V to 15V input voltage range, internal 1-A N-channel MOSFET, 0.205-V feedback reference voltage for low-loss current sensing, 1.6-MHz fixed switching frequency that enables small ceramic input/output capacitors and chip inductors, and a TTL-compatible enable/PWM dimming pin. The device includes internal compensation, cycle-by-cycle current limit, and thermal shutdown for robust operation in space-constrained lighting modules.
The architecture is a peak-current-mode controlled buck converter with internal compensation. The 1.6-MHz switching frequency is well above the AM radio band, simplifying EMI compliance for consumer products. The low 0.205-V reference across the external sense resistor keeps conduction loss below 1% of the LED current, which is critical in 1-A high-power LED applications where even 0.3V drop wastes 300 mW.
Typical applications include camera phone flash/torch LED drivers, portable LED flashlights, display backlighting, signage and architectural lighting, and any 1-A class high-brightness LED string on a 5V or single-cell Li-Ion bus. The small TSOT-23-6 footprint also suits wearable and IoT lighting nodes.
When designing with this part, choose the sense resistor with low-ESR tolerance (1% or better) to keep current setpoint accuracy within ±5%, and size the buck inductor to maintain continuous conduction mode at the minimum dimming duty. Keep the high-frequency loop (input cap, SW node, low-side ground) tight on the PCB to minimize EMI.
This page synthesizes distributor pricing, drop-in alternative options, and PCB-level design considerations that are not consolidated in the manufacturer datasheet, giving procurement and design engineers a single reference for evaluation.
Drop-in-Alternativen für LM3405XMKX/NOPB – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Varianten dieser Serie
Modelle derselben Serie, die drop-in-kompatibel sind mit LM3405XMKX/NOPB (gleiche Bauform und Footprint) – abweichend in Input Voltage Range, MSL Level, Switching Frequency, Topology.
Schnellvergleichstool – Wählen Sie Alternativbauteile für den Direktvergleich:
LM3405XMK/NOPB
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LM3405AXMK/NOPB
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LM3405AXMKE/NOPB
✅ Drop-In✓ Auf Lager
$0.66 / Stück
Datenblatt ansehen →LM3405XMKX/NOPB Grenzwerte & elektrische Eigenschaften
| Topologie | Step-Down (Buck), Constant Current |
| Anzahl der Ausgänge | 1 |
| Eingangsspannungsbereich | 3 V to 15 V |
| Output Current (LED) | 1 A (max) |
| Schaltfrequenz | 1.6 MHz (typ, internal) |
| Feedback Reference Voltage | 0.205 V |
| Internal MOSFET | Yes (N-channel, 1 A) |
| Dimming Control | PWM (EN/DIM pin, TTL) |
| Wirkungsgrad | Up to 95% (typical, application dependent) |
| Betriebstemperaturbereich | -40 C to +125 C |
| Gehäuse | TSOT-23-6 (DDC), 6 pins |
| Montageart | Surface Mount |
| MSL-Level | 1 |
| Thermisches Abschalten | Yes (internal) |
| Strombegrenzung | Cycle-by-cycle (internal) |
| RoHS-Status | Compliant |
LM3405XMKX/NOPB Pin-Konfiguration
| Pin 1 | EN/DIM — Enable / PWM dimming input (TTL-compatible, internal pull-up) |
| Pin 2 | GND — Ground return |
| Pin 3 | FB — Feedback (current sense, 0.205V reference) |
| Pin 4 | NC — Not connected (per datasheet) |
| Pin 5 | VIN — Input supply (3V to 15V) |
| Pin 6 | SW — Switch node (internal N-MOSFET drain) |
Typische Anwendungen
LM3405XMKX/NOPB ist geeignet für 6 Anwendungs: Camera Phone Flash/Torch LED Driver, Portable LED Flashlight, LCD Display Backlighting, Automotive Interior Lighting, IoT Smart Lighting Node, Signage and Architectural LED Strip.
Camera Phone Flash/Torch LED Driver
The LM3405XMKX/NOPB is a strong match for camera phone flash and torch LED drivers because it delivers a precisely regulated 1A peak current from a single-cell Li-Ion (3V-4.2V) input, with 1.6-MHz switching that places EMI above the camera sensor's sensitive band. The 0.205V reference across the external sense resistor keeps conduction loss below 1%, critical for flash events where 0.5-1.5A peaks must be sustained for 100-500 ms. The EN/DIM pin accepts a PWM signal from the camera ISP for fine brightness control in torch mode and a hard enable for flash mode, simplifying host software.
Empfohlen
Portable LED Flashlight
The LM3405XMKX/NOPB suits portable LED flashlight designs because its 3V-15V input range covers both single 18650 Li-Ion cells and 2-3 cell battery packs without a boost stage. The 1A constant-current regulation maintains constant lumen output as battery voltage sags from 4.2V down to 3.2V, eliminating the dimming effect common in resistor-biased flashlights. The TSOT-23-6 footprint fits inside tubular flashlight heads, and the EN/DIM pin can be tied to a tactile pushbutton with optional PWM for adjustable brightness levels.
Empfohlen
LCD Display Backlighting
The LM3405XMKX/NOPB is well suited to LCD display backlighting where uniform luminance across a parallel LED string is required. Its 0.205V reference and external sense resistor set the LED current to within ±5% across all LEDs in the string, eliminating brightness mismatch. The 1.6-MHz switching frequency keeps the converter above the AM broadcast band, simplifying EMI compliance for monitors and TVs that must meet EN 55015/CISPR 15 limits. PWM dimming on the EN/DIM pin maps directly to a backlight brightness control signal from the display controller.
Empfohlen
Automotive Interior Lighting
The LM3405XMKX/NOPB can drive automotive interior LED strings such as dome lights, reading lamps, and accent lighting from a 12V automotive bus. Its 15V maximum input tolerates load-dump transients up to the typical 16V clamp level, and the internal thermal shutdown protects against LED failure modes. The 1.6-MHz switching enables a small inductor that fits under the headliner or inside a door-trim LED module. Note that for AEC-Q100 qualified applications, the TI LM3405-Q1 variants or alternative automotive-grade LED drivers should be used instead of the standard part.
Empfohlen
IoT Smart Lighting Node
The LM3405XMKX/NOPB fits small IoT smart lighting nodes such as connected downlights and outdoor garden lights because its TSOT-23-6 package and 1.6-MHz frequency allow a complete LED driver circuit under 25 mm². The 3V-15V input range supports both battery-powered and mains-stepped-down supplies, and the low 6-mA typical quiescent current (when disabled) preserves battery life in standby. The EN/DIM pin can be driven directly by a GPIO from a wireless MCU for cloud-controlled dimming. The high switching frequency keeps EMI low for the integrated BLE/Wi-Fi radio band.
Empfohlen
Signage and Architectural LED Strip
The LM3405XMKX/NOPB is a cost-effective driver for signage and architectural LED strips, especially in 12V or 24V bus systems where multiple 1A LED zones need to be driven individually. The high 1.6-MHz switching frequency supports small ceramic-only capacitors, which is preferable in outdoor fixtures where electrolytic lifetime is a concern. The PWM dimming input enables per-zone brightness control from a central controller, and the 1A constant current maintains uniform brightness across long LED runs where forward voltage varies with temperature.
Empfohlen
Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für LM3405XMKX/NOPB – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | LM3405XMK/NOPB | LM3405AXMK/NOPB | LM3405AXMKE/NOPB |
|---|---|---|---|---|
| Package | TSOT-23-6 (DDC) | TSOT-23-6 (DDC) - same | TSOT-23-6 (DDC) - same | TSOT-23-6 (DDC) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Output Current (max) | 1 A | 1 A | 1 A | 1 A |
| Input Voltage Range | 3 V to 15 V | 3 V to 15 V | 3 V to 15 V | 3 V to 15 V |
| Switching Frequency | 1.6 MHz (internal) | 1.6 MHz | 1.6 MHz | 1.6 MHz |
| Feedback Reference Voltage | 0.205 V | 0.205 V | 0.205 V | 0.205 V |
| PWM Dimming | Yes (EN/DIM pin) | Yes | Yes | Yes |
| Reel Quantity | 3000 (XMKX suffix) | 1000 (XMK suffix) | 1000 (AXMK suffix) | 250 (AXMKE suffix) |
| Silicon Revision | Original | Original | A-revision | A-revision |
Wichtigste Unterscheidungsmerkmale
- 1.6-MHz switching enables sub-25 mm² total solution footprint (vs. Lower-frequency 1-A LED drivers (e.g. 500-kHz class))
- Low 0.205V feedback reference minimizes sense-resistor power loss (vs. Drivers using 0.5V or 1.0V reference voltage)
- TSOT-23-6 package with 1-A capability in 6 pins (vs. Larger SOT-23-6 or MSOP-8 LED drivers at 1A)
Designhinweise
The LM3405XMKX/NOPB uses a 0.205V feedback reference rather than the more common 0.1V or 0.5V. Choosing a sense resistor with 1% tolerance and low TCR (under 100 ppm/C) is critical to maintain current setpoint accuracy across temperature. A 0.1 ohm 2512-size resistor in parallel with a 0.1 ohm 0805 allows fine trimming at calibration. Do not exceed 15V on VIN; the internal MOSFET is not rated for automotive load-dump transients above this value.
Keep the high-frequency switching loop (VIN capacitor positive terminal to SW pin to GND return) as tight as possible, ideally under 5 mm of total loop length, to minimize radiated EMI. Place the input capacitor within 2 mm of the VIN pin and use a 1-uF X5R/X7R 25V ceramic. The exposed thermal pad on the TSOT-23-6 underside should be soldered to a copper pour of at least 10 mm² to keep junction temperature rise below 50 C at 1-A continuous load.
Estimated: at VIN=12V, VOUT=5V (LED forward voltage), and 1-A continuous load, the LM3405XMKX/NOPB dissipates roughly (12V-5V) * 1A * (1-efficiency) of additional heat. With typical 90% efficiency, internal dissipation is approximately 0.78W. The TSOT-23-6 (DDC) package has a theta_JA of around 50 C/W on a 1-oz 4-layer JEDEC test board, producing a 39 C junction temperature rise. Continuous 1-A operation is feasible with proper PCB copper, but for ambient temperatures above 70 C a 0.5-A derating is recommended.
Compliance-Informationen
RoHS and REACH compliant per TI product page. NOPB suffix indicates Pb-free (lead-free) and RoHS compliance. Standard part is not AEC-Q100 qualified; for automotive applications, choose a -Q1 variant or qualified alternative.
